Process for producing acetone

ABSTRACT

A process for producing acetone by catalytically oxidizing isobutyl aldehyde with an oxygen containing gas in the presence of a catalyst consisting of manganese oxide or manganese oxide and alkali metal hydroxide supported on activated alumina as carrier.

ilited States Patent 1191 Sakakibara et al.

PROCESS FOR PRODUCING ACETONE Inventors: Kozo Sakakibara; Kiyoshi Yasuda, both of Saitama, Japan Division of Ser. No. l99,7l6,1No v. 17, 1971, Pat. No. 3,804,902,

[30] Foreign Application Priority Data Nov. 21, 1970 Japan 45-103046 Dec. 30, 1970 Japan 45-122246 [52] US. Cl 260/593 R [51] Int. Cl. C.07c 49/08 [58] Field of Search 260/593 R [56] References Cited UNITED STATES PATENTS 3,579,575 5/l97l Bouniol..... 260/593 R X 1451 Dec. 17, 1974 2,393,532 H1946 Hearne et al. 260/593 R 1,970,782 8/1934 Swallen 260/593 R X Primary Examiner-Leon Zitver Assistant ExaminerJames H. Reamer Attorney, Agent, or FirmWoodhams, Blanchard and Flynn [57 ABSTRACT A process for producing acetone by catalytically oxi- 8 Claims, No Drawings 1 PROCESS FORPRODUCING ACETONE This is adivision of application Ser. No. 199,716, v

filed Nov. 17, 1971, now US. Pat. No. 3,804,902.

isobutyl aldehyde is a by-product of the process for preparing n-butanol from propylene as the raw material by an oxo synthesis. However, the isobutyl aldehyde has not been utilized effectively in industry, and almost the entire amount thereof has been consumed as a fuel.

' Accordingly, it has been desired to find some effective uses of isobutyl aldehyde, because the oxo process will thereby be established as a more complete industrial process and natural resources will be more effectively used. 1

it has been attempted to obtain methacrylic acid by catalytically dehydrogenating isobutyl aldehyde and oxidizing the resulting methacrolein. Further, it has also been attempted to convert isobutyl aldehyde into isopropyl alcohol and acetone by oxidation in the liquid phase (for example, refer to FrenchPatent Application No. 500/68, Nov. 25, 1968 now French Pat. No. 1,593,452. Furthermore, a process for converting isobutyl aldehyde to the raw material of the abovementioned oxo process by cracking catalytically isobutyl aldehyde (Referto J. Falbe; Angew. Chem, Int. Ed. 9 (2) 169( 1970)) has been proposed. However, in these processes, the isobutyl aldehyde has not been utilized effectively. Further, as an attempt to prepare acetone directly from isobutyl aldehyde by gas phase catalytic oxidation, there has been known 'a process de- An object of the present invention is to provide a catalyst composition to be used ina process for producing acetone from isobutyl aldehyde by a gas-phase oxidation reaction with good selectivity to acetone and at a low temperature.

Another object of the present invention is to provide a process for producing acetone from isobutyl aldehyde, in .which isobutyl aldehyde is completely consumed at a very low temperature and the selectivity for converting isobutyl aldehyde to acetone is increased, thus decreasing the amount of by-products.

According to the present invention, it has been found that the above objects can be attained by providing a catalyst composition comprising manganese oxide sup ported on activated alumina as a carrier.

I Further, it has also been found that the above objects can be more advantageously attained by providing a catalyst composition comprising manganese oxide and alkali metal hydroxide supported on activated alumina as a carrier. By using the above catalyst compositions of the present invention, there is provided a process for preparing acetone from isobutyl aldehyde very advantageously.

Accordingly, the present invention provides a pro-.

cess for producing acetone from isobutyl aldehyde which comprises oxidizing isobutyl aldehyde catalytie' c'ally by an oxygen-containing gas in the presence of a catalyst consisting of manganese oxide and activated alumina.

Further, thepresent invention provides a process for producing acetone from isobutyl aldehyde which cornprises oxidizing isobutyl aldehyde catalytically by an scribed in Japanese Patent Publication No. 6201/68, in

which isobutyl aldehyde is oxidized by molecular oxygen in the presence of a catalyst consisting of molybdenum oxide and one or more of oxides of iron, bismuth, antimony, tellurium and cobalt added thereto, at a reaction temperature of 230 380C. However, in this process, acetone is obtained only in a yield of less than oxygen-containing gas in the presence of a catalyst consisting of manganese oxide, alkali metal hydroxide and activated alumina.

. can be preferably used. As the activated alumina, alumina having a boehmite structure, which can be preso that it can not be practised industrially as an economical process. On the other hand, a process for preparing acetone which comprises oxidizing propylene by aliquid-phase reaction in the presence of palladium chloride catalyst is known as the HoechstWacker method and is practised industrially. However, the production of acetone should not be dependent only upon the abovementioned process from propylene as the starting material and another effective process should be-considered. Further, as mentioned above, it is important to produce acetone from isobutyl aldehyde as the raw ma terial in order to make the socalled oxo process complete as an industrial and economical process.

Thus, we have considered isobutyl aldehyde which has not been utilized sufficiently and have carried out various studies for establishing the process for preparing acetone industrially from isobutyl aldehyde'as the raw material, and, as the result, we have found catalyst compositions which are very effective as a catalyst for pared by water washing, drying and decomposing at a predetermined temperature an aluminium gel obtained by the hydrolysis of an aluminium salt with an alkali, is preferably used.

The method for supporting the catalyst compositionv on the carrier is not limited. The catalyst composition can be easily produced by known methods, that is, a

method which comprises adding alumina to an aqueous solution of a manganese salt or an aqueous mixture of a manganese salt and an alkali metal hydroxide, drying and molding, or a method which comprises preparing previously a catalyst consisting of a manganese salt and alumina and adding an alkali metal hydroxide thereto.

droxide is sufficient if it is in an amount of less than i one-tenth of the amount of manganese oxide in order 3 to conduct the reaction efficiently at a low temperature.

In producing acetone from isobutyl aldehyde by mols per mol. If the concentration of oxygen is increased beyond the above-mentioned upper value, the complete oxidation reaction of isobutyl aldehyde will be accelerated and the desired selectivity to acetone will be lowered.

Though oxygen can be used by diluting it with other inert gases, an oxygen containing gas, such as air, is satisfactorily used. Furthermore, it is possible to carry out the process operation safely by diluting oxygen further with steamor an inert gas such as nitrogen. As the diluting gas to be used in the present invention, steam is preferable, which can be used in an amount of 40-80% by volume.

it is desirable to maintain the reaction temperature as low as possible in order to obtain acetone in a good selectivity by the gas phase oxidation of isobutyl aldehyde, but a temperature in the range of l50-250C. is preferable. The contact time of the raw material gas with the catalyst can vary in the range of -10 seconds and it is preferably in the range of l-5 seconds. The reaction is usually carried out at a normal pressure, but it can be carried out under an increased pressure.

In the following, the present invention will be explained by concrete examples in which acetone is prepared in a high yield at a low reaction temperature by the catalytic oxidation of isobutyl aldehyde in the gas phase, but the scope of the present invention is not limited by these examples.

EXAMPLE 1 148.4 parts by weight of manganese acetate (Mn(CH COO) .4l-l O) were dissolved in 650 parts by volume of water. The solution was completely mixed with 1000 parts by weight of activated alumina (produced by Nikki Chemical Co.; boehmite structure; sintered at 600C: surface area: 200 m /g). To this dried activated alumina, stearic acid was added. The mixture was then molded to a tablet of the size of 5 mm X 5 mm. The molding was carried out at a compression ratio of H2 so' as to form tablets having a compression strength of 60-80 kg/cm. The resulting tablets consisting of manganese acetate activated alumina were calcined in air at 200C. for 1 hour and 350C. for 4 hours to obity of 81.0%, and at a reaction temperature of 250C, the corresponding figures were 96.0% and 72.0% respectively. Carbon dioxide gas and carbon monoxide gas were formed besides acetone, and very small amounts of acetaldehyde, acetic acid and methacrolein were recognized.

For the purpose of comparisomthe same treatment as described above was carried out under the same conditions, except that alundum (produced by Shikishima Marby Co.) or silica (precipitated silicic anhydride) was used as the carrier. The results obtained are shown in the following Table l, together with the results obtained when activated alumina was used.

Table 1 Results of reaction at 200C.

Carrier isobutyl aldehyde Acetone selecconversion rate tivity Alundum (tr-A1 0 56.5 69.8 Silica (SiO 92.0 48.0 Activated alumina 95.0 81.0

EXAMPLES 2 to 5 148.4 parts by weight of manganese acetate (Mn(CH COO) .4H O) were dissolved in 650 parts by X 5 mm. The tablets were calcined in air at 200C. for

1 hour and 350C. for another 4 hours to obtain a catalyst composition consisting of manganese oxide-sodium hydroxide-activated alumina. A stainless steel reaction tain a manganese oxide activated alumina catalyst. A

stainless steel reaction tube having an inner diameter of 27 mm was filled with 50 ml. of the catalyst. The raw material gas used had a composition consisting of 4.0% of isobutyl aldehyde, 8.0% of oxygen, 43.0% of steam and the balance of nitrogen gas. A catalytic reaction was conducted by passing this gas at a normal pressure through the reaction tube which contained the abovementioned catalyst so as to make the contact time to be 3 seconds. The result was as follows, that is, at a reaction temperature of 200C, there was an isobutyl aldehyde conversion rate of 95.0% and an acetone selectivtube having the inner diameter of 27 mm was filled with 20 ml. of this catalyst composition. The raw material gas used had a composition consisting of 4% of isobutyl aldehyde, 8% of oxygen, 43% of steam and the balance of nitrogen. This gas mixture was brought into contact with the above-mentioned catalyst at 250C. under a normal pressure so as to make the contact time to be 3.0 seconds. The results are shown in the following Table 2.

Table 2 Results of reaction at 250C.

Catalyst compositions were prepared by using sodium hydroxide, lithium hydroxide and potassium hydroxide in such an amount that the weight ratio of the alkali metal hydroxide to manganese oxide is made 0.080, respectively, in the same treatment as in Examples 2 to 5. The results are shown in the following Table Table 3 Ex- Kind of alkali lsobutyl aldehyde Acetone ample added conversion rate selectivity 6 Potassium hydroxide 93.0 82.0- 7 Lithium hydroxide 92.0 82.0 8 Sodium hydroxide 93.0 82.0

to 10 wt.% based on the carrier and the amount of alkali metal hydroxide is less than one-tenth of the amount of manganese oxide.

4. The process as claimed in claim 1, in-whichsaid mixture of oxygen and aninert diluent gas is air.

5. The process as claimed in claim 1, in which. said mixture of oxygen and an inert diluent gas is air diluted with steam.

6. The process as claimed in claim 1, in which said' alkali metal hydroxide is sodium hydroxide, hydroxide or lithium hydroxide.

7. The process as claimed in claim 1, in which the concentration of isobutyl aldehyde in the feed gas is l potassium to 20% by volume and the concentration of oxygen is V l to 5 mols per mol of isobutyl aldehyde.

8. The process as claimed in claim 1, in which the concentration of isobutyl aldehyde in the feed gas is l to 10% by volume and the concentration of oxygen is l to 3 mols per mol of isobutyl aldehyde. 

1. A PROCESS FOR PRODUCING ACETONE, WHICH COMPRISES CONTACTING GASEOUS ISOBUTYL ALDEHYDE AND A MIXTURE OF OXYGEN AND INERT DILUENT GAS, WITH A CATALYST CONSISTING OF MANGANESE OXIDE AND ALKALI METAL HYDROXIDE SUPPORTED ON ACTIVATED ALUMINA AS A CARRIER, AT A REACTION TEMPERATURE OF FROM 150 TO 250*C. FOR A CONTACT TIME OF FROM 0.5 TO 10 SECONDS.
 2. The process as claimed in claim 1, in which said activated alumina is of a boehmite structure.
 3. The process as claimed in claim 1, in which the concentration of manganese oxide in said catalyst is 0.1 to 10 wt.% based on the carrier and the amount of alkali metal hydroxide is less than one-tenth of the amount of manganese oxide.
 4. The process as claimed in claim 1, in which said mixture of oxygen and an inert diluent gas is air.
 5. The process as claimed in claim 1, in which said mixture of oxygen and an inert diluent gas is air diluted with steam.
 6. The process as claimed in claim 1, in which said alkali metal hydroxide is sodium hydroxide, potassium hydroxide or lithium hydroxide.
 7. The process as claimed in claim 1, in which the concentration of isobutyl aldehyde in the feed gas is 1 to 20% by volume and the concentration of oxygen is 1 to 5 mols per mol of isobutyl aldehyde.
 8. The process as claimed in claim 1, in which the concentration of isobutyl aldehyde in tHe feed gas is 1 to 10% by volume and the concentration of oxygen is 1 to 3 mols per mol of isobutyl aldehyde. 